Transmission assembly and control platform to be used in a transmission assembly

ABSTRACT

The invention relates to a transmission construction unit having a transmission housing, an electronic control apparatus assigned to the unit and having at least one electronic control device, and a hydraulic control apparatus. The electronic control device and the hydraulic control apparatus are arranged in the transmission housing in direct spatial proximity to one another on a joint carrying device.

FIELD OF THE INVENTION

The invention relates to a transmission construction unit. Furthermore,the invention relates to a control platform for use in a transmissionconstruction unit.

SUMMARY OF THE INVENTION

Transmission construction units, in which the change between theindividual gear states in specific driving situations is madeautomatically as a function of variables at least indirectly describingthe current driver's wish and/or the current driving situation, areknown in a multiplicity of versions. These are designed, for example, asconverter transmissions, comprising at least one hydrodynamic converterand mechanical rotational-speed/torque conversion devices, such as isdescribed, for example, in the Voith publication: “Hydrodynamik in derAntriebstechnik” [“Hydrodynamics in drive technology”], VereinigteFachverlage, Krauskopf Ingenieur Digest, Mainz 1987, pages 151 to 195.For the optimum adaptation of the transmission behavior, thetransmission construction unit is assigned a control apparatus for theelectronic activation of the individual rotational-speed/torqueconversion devices. In this case, the activation and operation of theactuating devices for changing the functioning are normally carried outhydraulically by means of a hydraulic control apparatus which may beintegrated at any desired point in the transmission. As regards couplingbetween the electric and the hydraulic control apparatus, there aretherefore a multiplicity of possibilities which, in addition to thedifferent construction space requirement, necessitate a considerablylarger line length. According to the versions of the prior art, thetransmission control apparatus is arranged separately from the housingof the automatic transmission in the vehicle. Since the housings of thetransmission construction unit and of the control apparatus are normallyproduced at different locations and are operatively connected to oneanother only during assembly in the vehicle, in each case randomlyselected transmission construction units are connected to a randomlyselected electronic control apparatus. Even when gear step-up orchange-over characteristic curves show a particular change or deviationin their initial characteristic in relation to a cut-in ratio of amagnet coil used for controlling the gear change, it may therefore notbe possible to correct these variations with the aid of the electroniccontrol apparatus.

In addition to transmission control apparatuses of this type, which arestructurally independent, transmission control apparatuses are alsoknown which are integrated into the vehicle management system, asdescribed, for example, in the publication EP 0 373 849 A2.

One disadvantage of the known transmission control apparatuses is that,for transmissions of the same type, the controls are always setidentically, in order, for example, to ensure easy exchangeability, thatis to say specific tolerances cannot be ruled out. Transmission controlapparatuses of this type are therefore not tuned to the transmissionconstruction unit installed individually in the vehicle. If, on theother hand, the transmission control apparatus is tuned to atransmission construction unit, the control, for example the ECU, has tobe reprogrammed correspondingly when the transmission is exchanged. Thisis highly labor-intensive.

Furthermore, the transmission control apparatuses known from the priorart are characterized in that, in order to make the necessary electricconnections, for example the electric connections between specificsensors detecting variables characterizing the current drivingsituations and/or sensors for detecting the driver's wish and anoverriding control apparatus and/or the transmission control apparatusand the actuators which, as a rule, comprise a hydraulic controlapparatus, a multiplicity of plug connections and lines have to beprovided. Consequently, because of the large number of possible faultsources, systems of this type have relatively low reliability. Also, theindividual elements of the transmission control apparatus and theircoupling to the hydraulic control apparatus require correspondingconstruction space, and these elements cannot be exchanged in a simpleway for elements of a different design.

The object of the invention is, therefore, to develop a solution for atransmission construction unit which avoids the disadvantages presentedabove and by means of which easily exchangeable units, in particular ofthe individual control apparatuses, both hydraulic and electric, arepossible at as low an outlay as possible. The solution according to theinvention is at the same time to be distinguished by a low outlay instructural and manufacturing terms.

According to the invention, in a transmission construction unit,comprising a transmission housing, a hydraulic control apparatus and anelectronic control apparatus assigned to the transmission constructionunit and comprising at least one electronic control device, theelectronic control device is arranged in the transmission housing indirect spatial proximity to the hydraulic control apparatus. Byelectronic control device is meant, in this context, the controlappliance or a unit of electric and electronic structural elements, towhich the variables necessary for activating the transmissionconstruction unit are fed and are processed in this, and which outputsregulating variables formed from the input variables according to thedesired activation operation. The control device comprises, as a rule, aplurality of electric and electronic structural elements which areassigned to one another according to the processing of the inputvariables which is to be carried out and are coupled to one another.Preferably, a plurality of the electric and/or electronic structuralelements are arranged jointly on at least one carrier plate and aresurrounded by a control device housing. In this case, there is thepossibility that the carrier plate is integrated completely in thecontrol device housing or else forms at least one part wall region ofthe control device housing.

The electronic control apparatus comprises, in addition to the controldevice, devices for detecting the input variables and means for couplingthe devices to the control device, furthermore means for coupling to thecorresponding regulating elements for actuating the regulating deviceswhich are assigned to the individual transmission elements of thetransmission construction unit for changing the functioning or operatingmode. Since the regulating devices in the form of actuators may also bean integral part of the hydraulic control apparatus, the coupling meansmay then be assigned both to the electronic and to the hydraulic controlapparatus.

According to a further aspect of the invention, the entire electroniccontrol apparatus is integrated in the transmission housing and isarranged in direct spatial proximity to the hydraulic control apparatus.This means that a plurality of, preferably all the devices for detectingone of the variables at least indirectly characterizing the drivingsituation and/or the functioning mode of the transmission constructionunit are also integrated in the transmission construction unit and arearranged in spatial proximity to the hydraulic control apparatus.

By hydraulic control apparatus are meant, in this context, the hydraulicconnections between the means of detection of an input variable and/orthe electric control apparatus and the regulating devices which, as arule, are acted upon hydraulically by a pressure, and the elementsfunctioning as actuators and their coupling to the regulating elements.Included at the same time are essentially all the elements to beactuated which are necessary for actuating or setting the individualgear stages.

The solution according to the invention affords the advantage ofincreased reliability, since the number and length of the lineconnections necessary for electric coupling are considerably smaller, ascompared with conventional solutions, due to the integration of thecontrol apparatus in the housing. Furthermore, by the electronic controlapparatus being arranged in the transmission construction unit,individual adjustment of the control apparatus to the respectivetransmission construction unit is possible, without a reprogramming ofthe control device having to be carried out in the event of an exchangeof the transmission construction unit. The unequivocal assignment of thetransmission construction unit and electric control apparatus makes itpossible to simplify the logistics. The structural integration of theelectronic and hydraulic control apparatus in the transmissionconstruction unit makes it possible to provide a testable unit of thecontrol apparatus, control hydraulics, actuator technology and sensortechnology of the transmission construction unit, the control apparatusbeing capable of being adapted to the transmission-specific toleranceseven during the test operation.

Preferably, the electronic control device and the hydraulic controlapparatus are arranged, in the installation position, below the axis ofsymmetry of the transmission. This affords the advantage that bothelements are easily accessible and exchangeable.

There is a multiplicity of possibilities as regards the two controlapparatuses, electronic control apparatus and hydraulic controlapparatus, being arranged spatially near to one another. It may beenvisaged, in this case, to have

-   a) an arrangement of the hydraulic control apparatus and electronic    control device or electronic control apparatus next to one another    in the horizontal direction and in one plane, that is to say without    offset, in the vertical direction;-   b) an arrangement of the hydraulic control apparatus and the    electronic control device or control apparatus next to one another    in the horizontal direction and offset to one another in the    vertical direction;-   c) an arrangement one above the other in the horizontal direction.

Preferably, in this case, each of the control apparatuses ordevices—electronic control device and hydraulic control apparatus—isassigned a corresponding carrier element, said carrier elements beingcapable of being connected to one another to form a carrying device, sothat a structural unit comprising at least the electronic control deviceand the hydraulic control apparatus can be formed. This can be removedas a whole from the transmission construction unit in a simple way. Afurther possibility is to arrange both, the electronic control device ofthe electronic control apparatus and the hydraulic control apparatus, ona central carrier element and likewise to form a structural unit. Inboth cases, the entire structural unit consisting of carrier element orcarrier elements, hydraulic control apparatus and electronic controldevice is designated as a control platform which can be offered as ahandleable structural unit.

According to the invention, a cooling device is assigned to the fueland/or control-means and/or lubricant circuit of the transmissionconstruction unit and is integrated in the transmission housing. Thiscooling device may be designed in various ways, but, as a rule,comprises either at least one cooler, one or more cooling elementsand/or a heat exchanger. In this case, the cooling device is arrangedpreferably next to or above or below at least one of the twoapparatuses—electronic control apparatus or electronic control device orhydraulic control apparatus—or between the two. Optimum cooling of theelectronic structural unit can therefore additionally be achieved.

To provide a particularly compact structural unit or for theparticularly simple routing of the hydraulic fluid, the hydrauliccontrol apparatus comprises a duct plate for the routing of oil for thehydraulic control, said duct plate being formed by the closing plate ofthe cooler or cooling device. According to a further aspect, the housingof the cooling device may be formed additionally from the oil pan of thetransmission construction unit and the duct plate of the hydrauliccontrol. This affords the advantage that, since these parts are presentin any case in an automatic transmission, a separate housing for thecooling device can be dispensed with. In a particularly advantageousversion, during the shaping of the oil pan, the housing of the coolingdevice is also shaped in such a way that the oil in the oil pan cannotenter the housing of the cooling device and, furthermore, the housingfor the cooling device is designed to be downwardly open in theinstallation position, so that the housing is closed as a result of theintroduction of the control platform. In this case, simpleexchangeability of the entire electronic and hydraulic control apparatustogether with cooling devices is possible without a high outlay in termsof assembly.

A further considerable advantage in the integration of the coolingdevice into the transmission construction unit is that complicated hoseconnections or pipe connections between the transmission and the coolingdevice may be dispensed with, as well as mountings by means of which thecooling device has to be fastened to the transmission construction unit.

In this case, when the transmission construction unit is in theinstallation position, the cooling device is integrated into the oil panin such a way that there is no need for any enlargement of the outertransmission contour, as compared with the conventional known solutions.An essential advantage of integration of this kind is that the overalltransmission construction unit can be fitted optimally and more easilyinto the increasingly smaller or available installation spaces.

Preferably, the cooling device, electronic control apparatus andhydraulic control apparatus are arranged on a common carrier element orelse each on its own carrier element, said carrier elements beingcapable of being assembled together with one another to form astructural unit, and form what may be referred to as a control platform.Preferably, furthermore, a large part of the detection devices, as arule designed as sensors, for determining the input variables of thetransmission construction unit which are to be processed in the controlapparatus or device is also arranged on the control platform or isintegrated in the latter, in order to provide an even more compactstructural unit which can easily be exchanged. In this case, the controlapparatus would likewise be arranged almost completely on the carrierelement.

According to a further aspect of the invention, in addition, furtherstructural elements, for example an oil pump with a suction filter, afine filter and all the oil connections and also the necessary sensors,are arranged on the control platform. This arrangement allows thecomplete cabling of all the actuators and sensors and separate testingof all the sensors and actuators, including the oil supply of plugconnections, irrespective of the integration of these functionalelements into the transmission construction unit.

According to a further aspect of the invention, the electronic controlapparatus is assigned a housing which is designed preferably to be tightto hydraulic fluid, for example oil and/or another fluid. The controldevice may then likewise be arranged in the oil sump of the transmissionconstruction unit. There is thereby the possibility of exposing theelectric and electronic structural elements of the control device to atleast indirect cooling by the fuel located in the fuel or oil sump ofthe transmission construction unit. However, in order to make theelectric connection between the control device and the sensors of thecontrol apparatus, which are necessary for detecting the variables atleast indirectly characterizing the current driving situation and/or thedriver's wish and/or further boundary conditions, and the actuators, tobe activated by means of the control apparatus, for actuating theindividual elements of the transmission construction unit, for examplein order to carry out the gear change and/or to stipulate inputvariables by means of an overriding control or regulating apparatus, theoiltight design of the housing makes it necessary to have acorrespondingly configured leadthrough on the housing. Preferably, inthis case, the individual contact elements or lines are led, embedded inan electrically nonconductive and fluidtight material, through thecontrol device housing, so that the penetration of harmful substancessuch as, for example, oil, is prevented.

The arrangement of the control device in the, in the installationposition, lower region of the transmission construction unit and theprovision of a corresponding housing make it possible to arrange thesensors for detecting the individual variables at least indirectlydescribing the operating mode of the individual elements of thetransmission construction unit at a specific time likewise in the regionbelow the transmission center line, which corresponds to the axis ofrotation, and therefore to make the entire control apparatus relativelycompact. The described arrangement in the oil sump, which, as a rule, isaccumulated in an oil pan which is formed by the lower part of thetransmission, makes it possible, furthermore, in a simple way to demountthe control apparatus, complete with the associated control hydraulics,the actuator technology for actuating the individual shift elements andthe sensors which, as a rule, are arranged on the housing of the oilpan, and to test it separately as an entire unit for functioningcapacity, if appropriate additionally under specific predefinableconditions.

To ensure the connection between the elements coupled to the controldevice, such as sensors, actuators and/or a further control apparatus,the connection between the individual contacts and the control device,in particular the electric structural elements arranged on the carrierplate in the form of an electronic board, is made in such a way thatthese contacts are designed as spring contacts, so that the springspress the contacts onto the contact points of the electronic board.Alternately, connections by means of soldered-on or welded wires or inthe form of pluggable connections may be produced.

The electric connections between the sensors, actuators and controldevice of the transmission construction unit may be designed in the formof

-   a) flexible cable connections and/or-   b) rigid conductor tracks consisting, for example, of copper.    As a rule, in this case, flexible cable connections are preferably    used, since these can be adapted in a simple way with regard to line    routing.

In order to prevent thermal overloading of the electronic controlapparatus due to the generation of heat in the transmission constructionunit, there is advantageously provision for the electronic controldevice, which is integrated in the housing of the transmissionconstruction unit, to be uncoupled thermally from said housing, forexample by means of a heat-insulating intermediate layer. The housing ofthe electronic control device is in this case, for example when arrangedin the oil sump of the transmission construction unit, protectedrelative to the oil sump by means of a heat-insulating medium against anexcessive transfer of heat from the hot oil to the electronic structuralelements. In this respect, there is a possibility either of providingthe housing with a coating consisting of a heat-insulating medium orelse of manufacturing parts of the housing wall from a heat-insulatingmaterial.

It is particularly advantageous, furthermore, not only to uncouple theelectronic control device thermally from the transmission constructionunit, but also vibrationally, for example by the electronic controldevice being suspended, vibration-damped, in the transmissionconstruction unit.

In a further developed embodiment, the control device is assigned meansfor the at least indirect discharge of heat from the electric structuralelements of the control device. These means function on the principle ofheat conduction or heat transfer. In the first-mentioned case, forexample, the carrier plates carrying the electronic structural elementsare connected highly heat-conductively to the bottom of the housing ofthe control apparatus. Preferably, for this purpose, a connection whichallows heat conduction is selected. This may be implemented, forexample, by means of an adhesive connection. Another possibility for thedischarge of heat by at least indirect cooling is to providecoolant-routing ducts which, by virtue of the transfer of heat from theelectronic structural elements to the coolant, discharge the heat fromthe electronic structural elements. The cooling ducts may in this casebe separate ducts in the form of tubular elements or lines. Preferably,however, the cooling ducts are incorporated directly into the wall ofthe housing of the control device. In this case, there is a possibilitythat, for example, as seen in the installation position in thetransmission construction unit, the bottom and/or the side walls and/orthe top side of the housing form the cover of a cooling-water duct or ofa cooling-water forward flow. There is a multiplicity of possibilitieswith regard to the arrangement of the coolant ducts or of the coolantlines. These may, for example, be an integral part of

-   a) an independent cooling circuit assigned to the control apparatus    of the transmission unit,-   b) the cooling circuit assigned to the transmission construction    unit,-   c) a cooling circuit assigned to another element in the vehicle,-   d) the vehicle cooling circuit.    It may also be envisaged to couple the separate cooling circuit of    the control device of the transmission construction unit to other    cooling circuits in the vehicle. To reduce the number of components    and the length of the lines to be provided for the purpose of    cooling individual assemblies, the coolant ducts or the coolant    lines of the control device of the transmission construction unit    are preferably integrated in a coolant circuit to be previously    provided.

The electronic control device comprises at least one input which can becoupled to the sensors provided for the at least indirect detection ofan actual value of a variable for a current driver's wish and/or otherdriving situation and/or a further control apparatus. Furthermore, atleast one output is provided, which can be coupled to the actuators, forexample in the form of control hydraulics for the actuation of shiftelements. When the housing of the control device is arranged in the oilsump of the transmission construction unit and the housing of thecontrol device has an oiltight design, corresponding apparatuses for theleadthrough of electric line connections or cables are to be provided.The cable leadthrough apparatus for implementing a transition of cablesfrom a region of space at least partially filled with a lubricant orfuel or the like, or containing residues and at least partiallysurrounded by a housing, to outside the region of space, comprises aninsulating body for the leadthrough of the cable elements, whichconsists of electrically nonconductive material and of an electricallynonconductive material impermeable to fluids.

The solution according to the invention makes it possible, furthermore,to provide a control platform as a structural unit which contains thehydraulic control apparatus, the electric control apparatus and thecooling device, including the actuators and sensors and also the oilcircuits. For this purpose, these elements are arranged on a commoncarrying device, which may also be formed from a plurality of carrierelements, and are preferably capable of being integrated in thetransmission housing of a transmission construction unit in the oil pan.As already stated elsewhere, this solution affords the advantage ofproviding testing of the hydraulics and of the functioning of theelectronic control, said testing being capable of being carried out,complete and self-contained, without integration into the transmissionconstruction unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The solution according to the invention is explained below withreference to figures, of which, presented in detail:

FIG. 1 illustrates, by means of a detail, a transmission constructionunit designed according to the invention, with a hydraulic andelectronic control apparatus;

FIG. 2 illustrates, in a diagrammatically simplified presentation, thesetup of a control platform for integration according to the inventioninto the transmission construction unit, in a top view;

FIG. 3 illustrates a view of the transmission construction unitaccording to FIG. 1 from the right;

FIGS. 4 a to 4 c illustrate in each case a top view of the oil pan withinserted cooling elements, of the duct plate and of a water box which isclosed by means of the duct plate and in which the cooling device isintegrated.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates, in a diagrammatically simplified presentation, adetail of a transmission construction unit 1, to which a control system2 is assigned in order to implement different operating modes, inparticular of the individual gear changes. For the sake of a simplifiedpresentation, no elements of the transmission construction unit 1, inparticular for implementing power transmission, are reproduced. Thecontrol system 2 comprises an electronic control apparatus 3 and ahydraulic control apparatus 4. The electronic control apparatus 3 andthe hydraulic control apparatus 4 are in this case, according to theinvention, arranged in direct spatial proximity to one another.Preferably, arrangement takes place below the axis of symmetry S of thetransmission. In this case, in the version presented, the arrangement ofthe electronic control apparatus 3 and of the hydraulic controlapparatus 4 in direct spatial proximity to one another is designed insuch a way that, as seen in the installation position, said apparatusesare arranged essentially next to one another in the transmissionconstruction unit 1. In the case presented, as seen in the installationposition, the hydraulic control apparatus is arranged so as to be offsetto the electronic control apparatus 3 in the vertical direction. Thereis, however, also the possibility, not presented here, of arranging theelectronic control apparatus 3 and the hydraulic control apparatus 4 ina common plane. In this case, in a preferred version, the electroniccontrol apparatus 3 and the hydraulic control apparatus 4 are mounted atleast indirectly on a jointly useable carrier element 5. The carrierelement 5 may in this case have a one-part or multipart design. In thecase presented, the latter has an at least two-part design and comprisesat least one first carrier subelement 5.1 and one second carriersubelement 5.2. In this case, the first carrier subelement 5.1 servesfor mounting the electronic control apparatus 3, while the hydrauliccontrol apparatus 4 is arranged on the second carrier subelement 5.2.The two carrier subelements 5.1 and 5.2 are capable of being connectedreleasably to one another to constitute a structural unit in the form ofthe carrier element 5.

The carrier element 5 carrying the electronic control apparatus 3 andthe hydraulic control apparatus 4 is integrated in the housing 6 of thetransmission construction unit 1 below the axis of symmetry S of thetransmission construction unit 1. Preferably, the electronic controlapparatus 3 and the hydraulic control apparatus 4 each have their ownhousing 7 and 8, and this may likewise be formed by the housing 6 of thetransmission construction unit. The carrier element 5 and therefore thecontrol system 2 may then be arranged in the region of a fuel or oilsump 9 in the housing 6 of the transmission construction unit 1. Thereis, at the same time, the possibility that the carrier element 5 can befastened in the wall region of an oil pan 10. It may also be envisaged,if the carrier element 5 is of suitable design, to have possibilitiesfor mounting or fastening on housing elements of the housing 6 of thetransmission unit 1 outside the oil pan 10 which, when the transmissionunit 1 is in the mounted state, is an integral part of the housing 6 ofthe transmission construction unit 1.

According to a further aspect of the invention, the control system 2 isassigned a cooling device 11. The cooling device 11 is likewiseintegrated in the transmission housing 6. In the particularlyadvantageous embodiment according to FIG. 1, the cooling device 11,which comprises at least one cooler 12, is integrated in the oil pan 10.Means 13 for thermal coupling of the cooling device to the controlsystem 2 are provided. In this case, the means for thermal coupling 13comprise at least one duct plate 14 for routing oil to the hydrauliccontrol or control apparatus 4, said duct plate being coupled to aclosing plate 15 of the cooling device 11. Preferably, the duct plate 14is designed at the same time as a closing plate 15 of the cooling device11. The closing plate 15 or the duct plate 14 is then an integral partof a housing 16 of the cooling device 11. Furthermore, in the casepresented, this housing 16 is formed partially by the oil pan 10. Inthis case, the duct plate 14, which is preferably designed at the sametime as a closing plate 15 of the cooling device 11, comprises at leastone, but preferably a plurality of ducts for routing the fuel of thehydraulic control apparatus 4. Cooling in this case takes place directlyor indirectly by heat conduction or heat transfer. Preferably, thecooling device 11 is in the form of a heat exchanger which may bedesigned differently in terms of its structural configuration and theimplementation of functioning. The cooling device 11 is in this casedimensioned such that no enlargement of the outer contour of thetransmission construction unit, as compared with conventional versions,is obtained. It thereby becomes possible for the transmissionconstruction unit 1 designed according to the invention, together with acontrol platform 17 designed according to the invention, which is formedby the carrier element 5 and carries the control system 2, to beintegrated into increasingly smaller installation spaces. Furthermore,by the arrangement of the cooling device 11 in the oil pan 10 beingstipulated, the possible number of variants in terms of possible coolerpositions is reduced considerably. Moreover, additional hose or pipeconnections between the transmission construction unit 1 and the coolingdevice 11 may be dispensed with. This also applies to mountings whichmay be necessary and by means of which the cooling device 11 has to befastened to the transmission construction unit 1, in particular thehousing 6. The cooling of the electronic control apparatus 3 is in thiscase carried out preferably in such a way that the coolant forward flow,not presented here, to the cooling device 11, in particular to theindividual coolers 12.1 and 12.2 designed as heat exchangers, isarranged in the housing 7 of the electric control apparatus. Preferably,the forward-flow duct is arranged in a housing wall of the housing 7 ofthe electronic control apparatus 3, in which case the forward-flow ductmay be routed on the bottom, side or top side of the housing 7.

A further possibility is the complete encasing of the electronic controland the thermal tie-up of the casing to the water-routing housing wallof the cooling device. The casing is separated from the rest of thetransmission by air gaps. To reduce the mechanical stress caused byvibrations, the casing is mounted in the transmission by means ofdamping elements.

FIG. 1 illustrates, in a diagrammatically simplified presentation, bymeans of a detail of a transmission construction unit 1, a preferredversion of the arrangement according to the invention of electroniccontrol apparatus 3 and hydraulic control apparatus 4 spatially near toone another, preferably together with the cooling device 11 additionallyprovided. However, the solution according to the invention is notrestricted to this version. Other arrangement possibilities may beenvisaged. Furthermore, there is a multiplicity of possibilities withregard to the actual embodiment of the electronic control apparatus 3and hydraulic control apparatus 4. For this purpose, the electroniccontrol apparatus 3 comprises at least one electronic control device 18which has at least one input 19 and at least one output 20. This isevident, for example, from FIG. 2 in a top view of a control platform 17configured according to the invention. In this case, the inputs 19.1 to19.N are coupled to devices 21.1 to 21.N for the at least indirectdetection of the current driving situation and/or a current driver'swish after a variation in the current driving situation and/or in theoperating mode of the transmission construction unit. The devices 21.Nare designed preferably in the form of sensors which convert thevariables at least indirectly characterizing the driving situationand/or the current driver's wish and/or the operating mode intocorresponding electric signals for processing in the electronic controldevice. The control device 18 in this case processes the signals presentat the inputs 19.1 to 19.N and correspondingly forms the regulatingsignals for activating the regulating elements for changing theoperating mode of the transmission construction unit 1. The regulatingsignals in this case form the input variables of the hydraulic controlapparatus 4. For this purpose, the hydraulic control apparatus 4comprises at least one, preferably a plurality of hydraulic controldevices 23.1 to 23.N which likewise have at least one input 24.1 to24.N, the inputs 24.1 to 24.N being coupled to the outputs 20.1 to 20.Nof the electronic control device 18 of the electronic control apparatus3. The regulating signal or regulating signals output at the output 20.1or in the outputs 20.1 to 20.N are used as a control signal or controlsignals for the hydraulic control apparatus 4. Via the hydraulic controldevice 4, for example in the form of at least one electromagneticallyactuable valve device, the control signal or control signals is or areused for activating the regulating elements 23.1 to 23.N in order tochange the operating mode of the transmission construction unit 1. Theseregulating elements 23.1 to 23.N are designated as actuators. Theseserve, for example, for actuating individual clutch and/or brake devicesof the transmission construction unit 1 which are to be actuated inorder to implement a gear change. Preferably, in this case, all theelements of the electronic control apparatus 3 and of the hydrauliccontrol apparatus 4 are arranged on the carrier element 5. It therebybecomes possible to achieve a complete cabling of all the actuators 23.1to 23.N and/or sensors 22.1 to 22.N to the electronic control device 18,thus affording the possibility of conducting a separate test of thecomplete unit comprising sensors, actuators, including oil supply andplug connection. The hydraulic control apparatus 4 is preferablydesigned in such a way that all the elements are likewise arranged withoptimum space utilization in relation to one another. It thereby becomespossible for the entire hydraulic control 4 of the transmissionconstruction unit 1, which may comprise, for example, a hydrodynamicrotational-speed/torque conversion device, shift elements and aretarder, to be combined in a single housing. The hydraulic transitionsto the transmission construction unit 1 and/or the design of the sensors22.1 to 22.N are in this case such that the mounting of the completestructural unit, that is to say of the control platform 17, can takeplace from below, that is to say below the axis of symmetry S of thetransmission, as seen in the installation position of the transmissionconstruction unit 1. Sealing is then carried out by means of insertabletubes or similar seals. After the removal of the control platform 17,therefore, all the structural elements in the vehicle which are arrangedabove the carrier element 5, in particular above the control platform17, can be maintained independently without the transmission beingdemounted. Preferably, for this purpose, the cooling device 11, all thenecessary detection devices 21.1 to 21.N, all the fuel or control-meansor lubricant connections and also additional elements, such as oil pumpand suction filter, are arranged on the control platform 17 next to theelectronic and hydraulic control apparatus.

In addition to the reduction in the length of the line connectionnecessary for electric coupling, in particular between the individualdevices for the at least indirect detection of a variable at leastindirectly describing the current driving situation and/or the operatingmode of the transmission construction unit and/or a driver's wish, theelectronic control apparatus and also the electronic control apparatusand the actuators, construction space to be made available can bereduced considerably. Furthermore, by the electronic control apparatusbeing arranged in the transmission construction unit 1, individualadjustment of the control apparatus to the respective transmissionconstruction unit is possible, without a reprogramming of the controldevice having to be carried out in the event of an exchange of thetransmission construction unit 1. The unequivocal assignment oftransmission construction unit and electronic control apparatus makes itpossible to simplify the logistics. Moreover, due to the integration ofthe electronic control apparatus into the transmission construction unit1 and to the direct spatial arrangement of the electronic controlapparatus 3, it becomes possible to provide a testable unit ofelectronic control apparatus, hydraulic control apparatus, includingactuator technology and sensor technology, of the transmissionconstruction unit 1, the individual control apparatuses, electroniccontrol apparatus and/or hydraulic control apparatus, being capable ofbeing adapted to the transmission-specific tolerances even during thetest operation.

According to a further aspect of the invention, further devices areintegrated in the control platform 17. These may be considered to be,for example, an oil pump with suction filter 26 and a fine filter 27.This becomes clear from FIG. 2 in a top view of a control platform 17configured according to the invention and from FIG. 3 in a view of atransmission construction unit according to FIG. 1 from the right.Furthermore, a gear pump 28, such as is used for the supply of fuel intransmission construction units 1, can be seen.

The version according to the invention, presented in FIG. 1, constitutesa preferred particularly advantageous embodiment of a control platform17. However, the invention is not restricted to this actual version.Other design possibilities may likewise be envisaged, which make use ofthe basic idea of the direct spatial arrangement of the electroniccontrol apparatus 3 and hydraulic control apparatus 4, preferably bothbeing arranged on a common carrier element 5.

FIG. 4 a illustrates, in a top view, a view of the oil pan 10 and thepart, shaped out of this, for receiving the cooling device 11. In thiscase, the housing of the oil pan 10 may be formed, for example, by thetransmission housing. It is also conceivable, however, for the oil panto be designed as a separate housing lower subelement which then, in theinstallation position, is mounted together with the remainingtransmission housing. The shaping of the wall regions 29 to form thehousing 16 of the cooling device may in this case be carried out in sucha way that a chamber 31 for receiving the cooling elements or coolingdevice 11 is produced, by the appropriate provision of an intermediatewall 30, in an oil pan 10 closed on one side. A further possibility, notpresented in detail here, is to leave the underside, not presented indetail here, open in the region of the chamber 31 in order to receivethe cooling device 11 on this underside and additionally to assign tothe cooling devices a closing plate which then closes the oil pan 10from below in the region of the chamber 31. Particularly when theelectronic control apparatus 3 and the hydraulic control apparatus 4 arearranged on a common carrying element 5, this solution is particularlyadvantageous, since it allows exchangeability without the completeseparation of the oil pan from the remaining transmission housing 16, inthat, only if necessary, both the cooling device 11 and the controlplatform 17 then arranged above it in the installation position,together with the electronic control apparatus 3 and the hydrauliccontrol apparatus 4, can be exchanged.

FIG. 4 b illustrates a top view of the closing plate 15 of the coolingdevice 11, said closing plate being designed at the same time, in aparticularly advantageous way, as a duct plate 14 for routing the ductsfor the hydraulic control apparatus 4. Individual ducts are designatedhere, for example, by 32.1 to 32.N. This duct plate 14 closes thechamber 31 relative to the interior of the transmission. For thispurpose, said duct plate is placed onto the wall regions 29 and can befastened to these.

FIG. 4 c illustrates at the same time a top view of the duct plate 14mounted on the chamber 31, preferably the duct plate 14 carrying theelectronic control device 18 next to the ducts 32.1 to 32.N.

The transmission unit may also include an input shaft 101 coupled to atleast some of the transmission elements. The input shaft 101 may besituated at a first height in the transmission housing, and thehydraulic and electronic control apparatus may be mounted in thetransmission housing below the height of the input shaft 101.

1. A transmission unit for a transmission having a plurality oftransmission elements that cooperate, the unit comprising: atransmission housing containing the transmission elements; adistribution circuit for delivering a fluid to the transmission elementslocated within the transmission housing; a hydraulic control apparatusmounted in the transmission housing and coupled to the distributioncircuit and operative to selectively distribute the fluid through thedistribution circuit to the transmission elements; an electronic controlapparatus mounted in the transmission housing in direct spatialproximity to the hydraulic control apparatus and operative to controlthe hydraulic control apparatus; a cooling device mounted in the housingin proximity to the hydraulic and electronic control apparatus, thecooling device having a closing plate provided with a plurality of ductsin flow communication with the hydraulic control apparatus for routingthe fluid towards the transmission elements; and an oil pan provided inthe transmission housing, and the cooling device being in the oil pan;wherein the oil pan includes a wall, and a cooling device housing forthe cooling device, wherein the oil pan wall defines the cooling devicehousing.
 2. The transmission unit defined in claim 1, further comprisingan input shaft to some of the transmission elements, the input shaftbeing at a first height in the transmission housing, the hydraulic andelectronic control apparatus are mounted in the transmission housingbelow the height of the input shaft.
 3. The transmission unit defined inclaim 1, wherein the hydraulic and electronic control apparatus aremounted next to each other in a horizontal direction.
 4. Thetransmission unit defined in claim 1, wherein the hydraulic controlapparatus and the electronic control apparatus are offset from oneanother in a vertical direction.
 5. The transmission unit defined inclaim 1, wherein the cooling device is mounted in the transmissionhousing next to the electronic control apparatus to prevent overheatingof the electronic control apparatus.
 6. The transmission unit defined inclaim 1, wherein the cooling device is mounted between the electroniccontrol apparatus and the hydraulic control apparatus.